Method of and means for processing mail

ABSTRACT

A method of processing mail is disclosed in which the mail is separated into categories by physical characteristics for processing regardless of the class thereof. A facility particularly adapted for processing mail in categories by physical characteristics is described including means for transporting, sorting and storing mail in each of such categories and subsequently releasing mail of all categories for a given destination for pickup by a carrier.

United States Patent Halopofl et al.. 51 Jan. 25 i972 [54] METHOD OF AND MEANS FUR 2,936,556 5/1960 Gibson ..209/l22 x PRUCESSING MAIL OTHER PUBLlCATlONS [72] Inventors: William f' 357 L05 Pinos W 0. P. Copping and T. R. Myers; The Mechanical Preparation San Jose 'f- 95123; ofMail...; Nov. 1958, pp. 725 729 ofMechanical Handling Hayward, Calif.

73 Assignee: said Hallopoff by said Wilson Primary Emmi'1erRihaYd Schacher An0rneyMe|lin, Moore & Weissenberger [22] Filed: Jan. 8,1970

[2!] Appl. No.: 1,463 [571 ABSTRACT A method of processing mail is disclosed in which the mail is [52] us Cl Q I I I I I I I I I I 209/124 separated into categories by physical characteristics for {51] lm. Cl 7/00 processing regardless of the class thereof. A facility particu- [58] Field larly adapted for processing mail in categories by physical 6 214/1 characteristics is described including means for transporting,

' sorting and storing mail in each of such categories and sub- [56] References Cited sequently releasing mail of all categories for a given destination for pickup by a carrier. UNITED STATES PATENTS 7 Claims, 12 Drawing Figures 2,696,919 12/1954 Gourdon ..2l4/l1 PATENTEUJAHZSIQYZ a 'eaT e g SHEET 10F 41 TRAYED MAIL- BUNDLED MAIL- ITEMS OF MAIL NoT LARGER THAN ITEMS OF NAIL DEsTINED FOR A 6"): II l/2"x v4" CONTAINED IN TRAYS. PARTICULAR POST OFFICE AND PACKAGED TOGETHER As A GROUP. SPR's 0nd FLATS PARCELS SMALL PARcELs, RoLLs AND FLATS ALL OTHER ITEMs OF MAIL EXCEPT HAvING A DIMENSION LARGER THAN THDsE REQUIRING sPEcIAL THOSE REQUIRED FOR TRAYED ITEMS HANDLING.

BUT SMALLER THAN A SHOE BOX AND WEIGHING LESS THAN TWO POUNDS.

MIXED MAIL INVENTORS I WILLIAM E. IHALOPOFF A MIXTURE 0F ITEMS of MAIL SUITABLE ROBERT M W'LSON FOR TRAYING WITH SPRs AND FLATS coNTAINED IN A MAIL BAG. w M flw ATTORNEYS PATENTEBJANZSIHTZ 3, 37,07

sum 2 BF 4 WILLIAM E. H OPOFF ROBERT M. WILSON FIG-A MW- ATTORNEYS METHOD OF AND MEANS FOR PROCESSING MAIL BACKGROUND OF THE INVENTION It has been estimated that two thirds of the worlds total mail is sent and received within the United States. In the year 1966 the U.S. Post Office handled some 75 billion pieces of mail and is expected to be handling 100 billion pieces of mail annually by the year 1980. The physical variety of such pieces of mail is immense, largely due to the fact that the U.S. Post Office is a public servant and, as such, is required to accept any article as mail which weighs less than pounds and which would not be harmful to the mails or to public morals as defined by law.

Classes of mail have been established by law, however, such classes have not been based on physical characteristics. Instead, classes of mail are apparently based on public policy as modified by political and revenue considerations. For example, any item weighing 20 pounds or less may be mailed as first class mail regardless of size and shape and must be mailed as first class mail if sealed against postal inspection. Items of second class mail are not subject to size and weight restrictions but must be newspapers" or other periodicals" which have been entered" as second class mail by the Postmaster General. An item of third class mail is not subject to any size restriction but must weigh less than 16 ounces and be open to postal inspection. Items of fourth class mail must be open to postal inspection, have a maximum size of 72 inches in girth and length combined, and weigh between 16 ounces and 20 pounds, subject to certain exceptions granting increased size and weight limits in the case of agricultural commodities, books, mailings by military personnel and sound equipment for use by the blind. Air mail and air parcel post may have a maximum size of 100 inches in length and girth combined and a weight up to 70 pounds. The foregoing discussion is not intended to be an exhaustive treatment of postal regulations relating to classes of mail but only to show that such classes of mail are only remotely concerned with the physical characteristics of items mailed in that certain maximum and minimum dimensions and weights are involved in defining the classes for revenue purposes.

It will be seen that a particular item might be mailed in any one of several classes. For example, a magazine might be sealed in an envelope and mailed as first class mail, or, if not sealed in an envelope, it may be entered" with the Postmaster General and sent as second class mail, or if not entered" it may be sent as third class mail if it weighs under 16 ounces or fourth class mail if it weighs over 16 ounces. If sent by air, whether sealed or unsealed, it would be air mail if it weighs less than 8 ounces or air parcel post" if it weighs over 8 ounces.

It is a general object of this invention to provide a method of and means for handling mail in accordance with certain physical characteristics of the items themselves ratherthan the legal class of mail in which such items may fall, whereby the efficiency and economy of the existing postal system may be improved.

In the existing U.S. Postal System there are some 45,000 post offices which are divided into 553 postal districts each with a centrally located facility called a sectional center facility" which serve the post offices located in their respective postal districts as required. Each post office, of course, sorts mail according to the ultimate recipient thereof in the local area which it serves. However, the extent to which a post office sorts mail going out ofits local area depends on the size of the post office in terms of revenue and other considerations. For our purposes it is sufficient to note that some post offices do not sort the mail going out of their local areas at all, but send it to the sectional center facility for the postal district in which they are located for further processing. Other post offices sort mail not only to the various sectional center facilities other than their own but also to larger post offices throughout the country. The sectional center facilities thus must be capahle of performing a variety of mail-handling services depending on the post offices they serve. I

It is a further object of this invention to provide an improved method for processing mail at sectional center facilities wherein each sectional center facility sorts mail received by it only to other sectional center facilities in addition to those post offices located within the postal district served by such sectional center facility.

According to this invention each sectional center facility processes the mail received by it on the basis of physical characteristics and comprises a facility appropriate for separating all mail into certain categories each having common physical characteristics. Thus, it is another object of this invention to provide a sectional center facility suitable for handling mail on the basis of the physical characteristics of categories thereof.

DESCRIPTION OF THE DRAWING The foregoing objects and features of this invention and the advantages thereof as well as other objects, features and advantages will become more clearly apparent from the following detailed description of the preferred embodiment when read in conjunction with the attached drawing wherein:

FIG. I is a graphical representation of the method and means of this invention including appropriate legends;

FIG. 2 is a top plan view of a facility in accordance with the preferred embodiment of this invention;

FIG. 3 is a side view in elevation of the facility in ac cordance with the preferred embodiment of this invention shown in FIG. 2;

FIG. 4 is an enlarged fragmentary sectional view taken along line 44l in FIG. 2;

FIG. 5 is a fragmentary plan view of the first level of the facility in accordance with the preferred embodiment of this invention taken along lines 5-5 of FIG. 4;

FIG. 5A is a fragmentary cross-sectional view of such first level;

FIG. 6 is a fragmentary plan view of the second level of the facility in accordance with the preferred embodiment of this invention taken along lines 6-6 of FIG. 4;

FIG. 6A is a fragmentary cross-sectional view of such second level;

FIG. 7 is a fragmentary plan view of the third level of the facility in accordance with the preferred embodiment of this invention taken along lines 77 of FIG. 4;

FIG. 7A is a fragmentary crosssectional view of such third level;

FIG. 8 is a fragmentary plan view of the fourth level of the facility in accordance with the preferred embodiment of this invention taken along line 8-8 of FIG. 4 and broken away to show the fifth level.

FIG. 8A is a cross-sectional view of such fourth and fifth levels.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, this invention is based on the discovery that, in spite of its apparent diversity in physical characteristics, the mail may be divided into five basic categories as indicated by the legends. Thus considering a piece of mail as being any item which must be handled separately from all other items, it has been found that pieces of mail having maximum dimensions less than 6 inches wide by l l-/: inches long and one-fourth of an inch thick constitute approximately 60 percent of the total volume of the mail by piece although they only constitute approximately 10 percent of the total volume of mail by weight. Such pieces of mail may be conveniently placed in trays as will be discussed more fully hereinafter for transportation and further processing. Similarly, it has been found that pieces of mail comprising substantial numbers of items of mail all destined for one post office and bundled together into a single piece at the source thereof constitute approximately l0 percent of the total volume of the mail by piece although they constitute approximately 25 percent of the mail by weight. It also been found that pieces of mail which are individual items having one of their dimensions greater than 6 inches wide by l linches long and one-fourth of an inch thick, but smaller than a shoe box and weighing less than 2 pounds per item, constitute about 25 percent of the total volume of mail by piece although only about 10 percent of the total volume of mail by weight. Such items are conveniently referred to as small parcels, rolls and flats (SPRs and flats). Finally it has been found that the balance of the mail consists of parcels weighing up to 70 pounds and having dimensions larger than a shoe box. Such parcels make up only about 1 percent of the total volume of mail by piece but constitute approximately 40 percent of the total volume of the mail by weight. Of such parcels, a very small fraction are so unusual in their physical characteristics (such as automobile tires or bundles of mops) as to be classified as outsides requiring special handling. In addition, a very small percentage (i.e., of the order of 5 percent by piece and by weight) of the total volume of the mail is Special Delivery mail which may fall in any category by physical characteristics and which must be handled other than in accordance with the teaching of this invention. Finally there are certain special processing steps that must be performed on a small percentage of the mail regardless of its physical characteristics. For example, bundled mail must be checked for weight; registered and certified mail must be recorded; metered, franked and penalty mail must be checked for compliance with postal regulations, etc.

As indicated in FIG. 1 the four categories by physical characteristics of the mail are handled separately according to the teaching of this invention. In addition, a fifth category of mail resulting from the present operation of the total postal system must be taken into account. Such fifth category is referred to herein as mixed mail and is a mixture of those pieces of mail which are suitable for placing in trays with those pieces of mail falling in the category of SPRs and flats. Such mixed mail is generated at post offices which do not have facilities for placing mail in trays and instead place all small individual pieces of mail together in a common mailbag for further processing. However, it will be understood that as used herein the term mixed mail is used to designated such a mixture of items of mail regardless of the type of container in which they are placed.

Another basis of this invention is the realization that the sorting of mail could be far more efficiently conducted if concentrated at facilities specifically designed for the purpose of processing mail. For example, if each of the existing sectional center facilities were properly designed they could easily handle the sorting of mail for all post offices within their postal district. Thus, FIG. I is a graphical representation of such a mail sorting facility designed to be capable of processing all mail for a substantial area such as a postal district and designed to process mail in accordance with categories of physical characteristics as described above.

As indicated by the graphical representation of FIG. I of FIG. 1 mail will be received by a facility embodying the method and means of this invention from two different types of sources as represented at A and B. Firstly, mail will be received from the post offices located within the postal district served by the facility. Secondly, mail will be received from other facilities located in other postal districts.

The first step in the method of this invention is to separate that mail which requires special processing from the main body of the mail as represented at C. Thus all bundled mail and mail of all classes carrying metered postage or permit postage must be weighed in order to determine whether or not the postage applied is correct. Similarly, registered mail and certified mail must be recorded. Finally, special delivery mail and certain items of mail, such as automobile tires for example, having extremely unusual physical shapes must be handled entirely independently of the method and means of this invention. Upon completion of the special processing steps all mail other than that requiring special handling is returned to the main body of the mail for further processing in accordance with this invention as represented at D. It should be understood that mail requiring special processing has been found to constitute something less than 10 percent of the total volume of the mail and that the portion of the mail requiring special processing which also requires special handling constitutes a small fraction of that 10 percent.

The main body of the mail, including all mail which has been subjected to special processing and returned thereto, is then divided into the five basic categories by physical characteristics described above and shown by the legends in FIG. 1 regardless of the physical class into which such mail may fall. It will be understood that mixed mail is received only from post offices and not from other facilities. According to the teaching of this invention each category of mail is then sorted in accordance with its ultimate destination in a physically distinct area of the facility. This enables appropriate equipment to be concentrated in such physically distinct areas for handling the particular category of mail assigned thereto. According to this invention each category of mail is sorted either to the post offices located within the postal district served by the facility or to other facilities in other postal districts. All mail destined to a post offlce in the postal district served by the facility is designated as incoming" mail and all mail for other facilities in other postal districts is designated as outgoing mail. As represented in FIG. 1 and more fully described hereinafter, the incoming mail and the outgoing mail are handled separately in view of the fact that the number of ultimate destinations for incoming mail will be far less than the number of destinations for outgoing mail. All categories of mail regardless of physical characteristics which have been sorted to a particular destination are then stored together in a group until picked up for delivery to such destination.

As suggested by the graphical representation of FIG. I the method of this invention is particularly suited for practice by means including circular carousels for the transportation of mail within the facility. Thus, as will be more fully described hereinafter, the preferred means of this invention includes six carousel-type conveyors, which conveyors are an integral part of the sorting and distribution functions of the facility. Thus all mail received by the facility is loaded onto a receiving carousel-type conveyor 41 by category according to physical characteristics as described hereinabove. The receiving carousel distributes such mail by category to the particular area designated for the further processing of each category. A first pair of carousel-type conveyors 42 and 43 are used to distribute the incoming and outgoing parcels to their appropriate storage location after they have been sorted by destination. Similarly a second pair of carousel-type conveyors 44 and 45 are utilized to distribute all other mail to appropriate area for storage after it has been sorted by destination, one of such carousels being used for incoming distribution and the other of such carousels being used for outgoing distribution. Finally a sixth carousel-type conveyor 46 is used to collect all stored mail for a particular destination and deliver it to a particular point for pick up. Although the use of such a will call distribution carousel is not absolutely essential in practicing the method of this invention it is particularly useful in insuring that the means of this invention may be operated at its fullest efficiency.

Referring to FIG. 2 a plan view of the preferred facility for practicing the method according to this invention is shown. Such preferred facility comprises a circular building 10, as shown in FIG. 3, and preferably comprises a main portion 11 having at least four levels or stories, one level 12 of which, may be a basement level. A penthouse level 13 is located on the roof of the main portion 11. As shown, the penthouse level is provided with an overhanging roof thereby forming a protected receiving dock 14 where mail may be unloaded onto the receiving carousel 4] for distribution according to category by physical characteristics. Access to the receiving area is provided by a circular ramp 15 about the outer periphery of the building 10.

The main portion 11 of the building may also be provided with an overhanging roof in order to form a protected loading area 16 for the pickup of mail at the lower level I2 of the facility after it has been processed therethrough. When such lower level i2 is below ground, appropriate access to the pickup area may be provided by a down ramp 7 as indicated in FIGS. 2 and 3.

In addition to being particularly suited to the use of circular carousel-type conveyors, a multilevel building as shown in FIGS. 2 and 3 enables the use of gravity in transporting the mail through the facility as described hereinafter and provides working space which is peculiarly suited to the handling of mail as will be more fully described hereinafter. In addition the circular facility shown in FIGS. 2 and 3 may be conveniently divided into sectors ltl as indicated by the dotted lines in FIG. 2. According to the preferred embodiment of this invention each sector may be provided with sufficient equipment to enable it to operate independently of the other sectors in the processing of mail. Thus, the mail handling capability of the facility may be scaled up or down with the dramatic fluctuations in the volume of the mail which inherently occur, by using only the number of sectors required by the volume of mail at any particular point in time. Thus the following figures of the drawing and discussion are directed to a single sector of the facility except as otherwise noted.

The physical size of the building and the number of sectors into which it is divided is, of course, determined by the volume of the mail which it must handle. The primary consideration in this regard is the area required to provide storage for each of the destinations to which mail will be directed from the facility. As mentioned hereinabove the postal system now comprises some 45,000 post offices divided into 553 postal dis tricts each with a sectional center facility. According to the teaching of this invention and assuming that each sectional center facility is adapted to utilize the method and means of this invention such facilities would currently be expected to distribute mail to approximately 650 destinations (i.e., 553 other sectional center facilities and a maximum of 100 post offices). Thus the provision of l,000 storage areas at a particular facility should allow for the predictable increase in volume of mail and in number of postal facilities or destinations. Accord ing to the preferred embodiment of this invention a building having a diameter of700 feet and an overall height of approximately 100 feet including the lower level would enable the provision of a thousand storage areas each having approxi mately L656 cubic feet volume thus providing a total storage volume of some 1,656,000 cubic feet. Since such storage volume is only required to hold mail until called for to be delivered to its destination, our studies indicate that such storage volume should easily enable the facility to handle mail volume of the order of 6 million pieces per day whereas mail volume of some 2 to 3 million pieces per day are the maximum presently being experienced by sectional center facilities.

Referring now to FIG. 4 a cross-sectional view of one of the sectors of a facility in accordance with the preferred embodiment of this invention is shown.

As shown the facility includes five levels which for discussion hereinafter will be numbered from top to bottom, the top level being considered the first level and the bottom level being considered the fifth level. Thus it will be seen that the carousel-type receiving distribution conveyor All is located in the receiving area 114 on the top or first level of the facility. The second level of the facility includes areas for the storing of parcels, the culling of mixed mail and the sorting of trayed mail. The third level includes the pair of conveyors 42 and 43 for distribution of incoming and outgoing parcels, respectively, and the pair of conveyors M and 45 for distribution of all other incoming and outgoing mail, respectively. The fourth level includes the storage areas for the various destinations served by the facility and the fifth level includes the carousel type will call" distribution conveyor 46 located in the loading area 16. The various chutes or gravity conveyors communicating between the various levels shown in FIG. 4 will be more fully described hereinafter.

Referring to FIGS. 5 and 5A a plan view of the top or first level and a cross-sectional view thereof are shown. The loading area M provides space for accommodating I00 semitrucks 50 for unloading. Such space is distributed about the outer periphery of the carousel-type receiving distribution conveyor ii and thus trucks 50 bringing mail to the facility may proceed to any point about the periphery of the carousel ill without preference. As shown the receiving carousel is divided into a plurality of sets of compartments each set consisting of five compartments 5ll-5 into which the mail is loaded by category according to physical characteristics. Thus. for example, all trayed mail would be loaded into compartment Sll of each set, all SPRs and flats would be loaded into compartment 52 of each set, all mixed mail into compartment 53 of each set, all bundled mail into compartment 54 of each set and all parcels into compartment 55 of each set. Such compartments 511-55 may be labeled or painted different colors in order to indicate the category of mail to be loaded therein. It will be understood that the mail from a particular truck may be loaded into any set of compartments as they pass the location of the truck whether such compartments already contain mail from other trucks or not. Furthermore the mail from a particular truck may be loaded into any combination of compartments in any combination of sets of compartments so long as each category of mail is placed in a compartment designated therefor.

A means 56 for bypassing the receiving carousel 41 is provided so that mail requiring special processing may be conveyed to the area 57 contained within the receiving carousel 41. All of the equipment required for performing such special processing may be located within the area 57 and upon completion of such special processing all mail which does not require special handling may be returned to the receiving carousel 411 via the bypass means 56. Any mail requiring spe' cial handling may be distributed directly from the special processing area 57 by hand or by other appropriate means. It will be seen that a central portion 58 of'the upper level will be available for use as a utility area or for other purposes as required.

According to this invention the receiving carousel all is provided with means for discharging each of the compartments 51-55 of each set of compartments :at different locations about the periphery of the conveyor 41. For example, gravitytype chutes, as represented generally at 59 in FIG. 5A, may be provided in sets of five with each chute of each set being gated to receive the mail contained in a different one of the five compartments of each set on the receiving carousel ll. It will be understood that there will be a set 59 of five such gravity chutes located within each sector 118 into which the facility is divided and that means may be provided for causing all of the sets of compartments of the receiving carousel 41 to be gated into the set of five gravity chutes associated with one particular sector of the facility or to be gated into the sets of gravity chutes of each sector as they are reached by the sets of compartments of the receiving carousel 41.

A set 59 offive gravity chutes is best shown in FIG. 6. It will be seen that such set 59 consists of two inclined gravity chutes 6ll and 62 extending from the inner periphery of carousel ill to the central portion of the second level, two spiral'type gravity chutes 63 and 66 extending from the inner periphery of the receiving carousel 41 through the second level to the third level of the facility and a spiral-type gravity chute having only one half turn and extending from the inner periphery of the receiving carousel 41 to the outer peripheral area of the second level. One of the inclined gravity chutes 61 is adapted to receive the trayed mail from the receiving carousel 4H and conduct it to the portion of the central area of the second level of the facility where such trayed mail will be separated into incoming and outgoing portions for further processing. The other of the inclined gravity chutes 62 is adapted to convey mixed mail from the receiving carousel M to the portion of the central area of the second level where it will be culled to separate the SPRs and flats from the mail suitable for traying as described hereinabove. One 63 of the spiral-type gravity chutes is adapted to convey bundled mail from the receiving carousel ii to the third level of the facility for further processing. The other 64 of the spiral type gravity chutes is adapted to convey SPRs and flats from the receiving carousel 41 to the third level of the facility for further processing. It will be noted that such other 64 spiral-type gravity chute is also adapted to receive an input of SPRs and flats from the culling area 66 on the second level as indicated at 67. The half-tum spiral chute 65 is adapted to receive parcels from the receiving carousel 41 and conduct them to the outer peripheral portion 68 of the second level of the facility for further processing.

Parcel-processing area 68 includes appropriate equipment for sorting the parcels according to their destinations and for separating the parcels into incoming and outgoing groups of destinations as defined hereinabove. A first inclined gravity chute indicated generally at 69 is provided at the outer periphery of the area 68 and communicates between such area and the outgoing carousel-type distribution conveyor 43 on the third level of the facility. Similarly an inclined gravity chute 70 depending opening at the inner periphery of the area 68 communicates between the area 68 and the carousel-type distribution conveyor 42 on the third level of the facility. It will be seen that by locating the parcel-handling area 68 in the outer peripheral portion of the facility it will inherently have a larger area than if it were located toward the center of the facility. This is highly desirable since parcels by their nature will tend to have a larger physical volume per piece than will the mixed mail and trayed mail which is handled in the central portion of the facility. Similarly the number of destinations for the outgoing portion of the parcels will tend to be greater than the number of destinations for the incoming portion of parcels as explained above. Thus the inclined chute 69 for conveying outgoing parcels from the parcel sorting area 68 to the distribution carousel 43 is located at the outer peripheral portion of the area 68 and the inclined chute 70 for conveying the incoming parcels to the incoming distribution conveyor 42 is located at the inner peripheral portion of the area 68.

Referring now to the central portion of the second level of the facility, an outgoing letter sorting machine 71 is provided adjacent the culling area 66. All SPRs and flats are separated or culled from mail suitable for traying and loaded into spiral chute 64 as indicated at 67 to be directed to the third level for further processing. All mail suitable for traying which is received in the culling area 66 is placed in the letter sorting machine 71 where it is faced, edged, canceled, sorted and trayed. Most of such mail will be directed to destinations outside the local area of the facility. Thus such mail after traying will be placed on an inclined gravity chute communicating between the letter sorting machine 71 and the outgoing conveyor 45 located on the third level of the facility. Such inclined chute is represented generally at 73 in FIG. 6 and shown in greater detail in FIG. 7A. A certain amount of the mail sorted in the letter sorting machine 71 will be directed to destinations within the local area of the facility. Such mail will be directed to an incoming letter sorting machine 72 after being faced, edged, canceled and trayed in letter sorting machine 71. After being retrayed according to local destination in the incoming letter sorting machine 72, the mail is delivered to an inclined chute 74 communicating between letter sorting machines 72 and the incoming distribution conveyor 44 located on the third level of the facility.

It will be understood that all trayed mail received by the facility will be received from other facilities and will be incoming mail destined for post offices within the postal district served by the facility. Thus, all such trayed mail is carried by inclined gravity chute 61 directly to the incoming letter sorter 72 and having already been faced, edged and canceled, it will simply be sorted and retrayed by local destination and sent to the incoming distribution conveyor 44 by inclined gravity chute 74.

Referring now to FIGS. 7 and 7A it will be noted that the incoming distribution carousels 42 and 44 for parcels and other mail, respectively, are of smaller diameter than the outgoing distribution carousels 43 and 45. As mentioned hereinabove this arrangement is inherently suited to the fact that the number of incoming destinations will be substantially smaller than the number of outgoing destinations. The distribution carousel may be divided into compartments and appropriate means may be provided for designating each such compartment for a particular destination. In the preferred embodiment such designation would be accomplished by appropriate electromechanical equipment in which case it may not be necessary to physically divide the distribution carousels into compartments since a particular area or arcuate length of such carousels might be coded for a particular destination at any particular point in time. As will be more fully explained in connection with FIGS. 8 and 8A each destination served by the facility is provided with a storage area to which mail is distributed by the distribution carousels. Thus mail loaded onto the distribution carousels 42-45 is carried to an appropriate point about the periphery of the facility at which it is automatically removed from the carousels for deposit in the appropriate storage area.

That area of the third level of the facility which is contained between the inner periphery of distribution carousels 43 and 45 and the outer periphery of distribution carousels 42 and 44 in each sector 18 of the facility is divided into two areas 75 and 76. The spiral gravity chute 63 which receives bundled mail from the receiving carousel 41 opens into area 75 and the spiral chute 64 which receives SPRs and flats from the receiving carousel 41 and from the culling area 66 of the second level of the facility opens into the area 76. Thus the area 75 is used for the sorting of bundled mail and the area 76 is used for the sorting of SPR's and flats. As shown generally at 77, direct access to the incoming and outgoing distribution carousels is provided from the area 75 whereby bundled mail may be loaded onto such distribution carousels after being sorted by destination. Similarly, as shown generally at 78 direct access to the distribution carousels 44 and 45 is provided from the area 76 for the loading of SPRs and flats onto such carousels after sorting by destination. The loading of bundled mail and SPRs and flats onto the carousels 44 and 45 is accomplished in the same manner as was described in connection with parcels and trayed mail.

As shown in FIG. 7 a peripheral area 79 is provided adjacent the outer periphery of the incoming distribution carousel 42 and peripheral areas 80 and 81 are provided adjacent the inner periphery and outer periphery, respectively, of the outgoing distribution carousel 43. As more clearly shown in FIG. 7A these peripheral areas 70, 80 and 81 include inclined worktables communicating with the incoming parcel carousel 42 and the outgoing carousel 43, respectively. It should be noted at this point that these areas and inclined tables are not peculiarly associated with any sector 18 of the facility. Instead they are in continuous operation for the full circumference of the facility and are adapted to allow parcels distributed by the carousels 42 and 43 to be containerized prior to being placed in storage. Thus as parcels are carried around the circumference of the facility by the carousels 42 and 43 they are automatically unloaded therefrom at a point about the periphery corresponding to the location of the storage area for the destination to which they are directed. At such point they are manually loaded into mailbags or other containers and dropped directly into chutes 82 which communicate with the storage area for the destination to which they are directed. It will be understood that SPRs and flats are also containerized prior to being loaded on distribution carousels 44 and 45. Containerization of bundled mail prior to loading on carousels 44 and 45 is generally unnecessary since such bundled mail is inherently of large dimension and weight.

SPRs, flats and bundled mail distributed by carousels 44 and 45 may be automatically discharged into inclined gravity chutes 82 corresponding to the destination to which they are directed by appropriate electromechanical equipment. Such storage areas are best shown in FIG. 8A and may comprise simple bins 83 mounted on an inclined plane and extending between the fourth level and the fifth level. Such bins may be adapted to receive mail from carousels 42-45 at their upper end and discharge mail through an appropriate gate at their lower ends onto the will call distribution carousel 4M5 located on the fifth level of the facility. The fifth level of the facility also includes the loading area 16 about the outer periphery of the will call distribution carousel as providing space for 100 semitrucks 50. It will be understood that the trucks may proceed to any point about the periphery of the will call carousel 46 with preference and through the operation of appropriate controls M the storage bin 83 (or bins) containing mail directed to the desired destination may be gated to discharge their contents onto the will call carousel d6. The control M may also be adapted to cause the will call carousel 46 to discharge the mail at the point where such control M is located for loading onto a truck Slit.

lt will be seen that a facility in accordance with the preferred embodiment of this invention enables mail to be delivered to the facility at any point about its periphery without preference and allows mail to be received from the facility from any point about its periphery without preference, thus tending to avoid any traffic complications due to the arrival of a large number of trucks at the facility during periods of peak mail volume. The facility is also inherently suited to the handling of mail in categories by physical characteristics in that the areas thereof may be matched to the physical and numerical volume of such categories of mail. The facility is particularly adapted for the use of gravity in conveying mail therethrough and for the use of circular carousels in the sorting and distribution of mail therein. Furthermore the physical dimensions of the facility are such that the velocities of the carousels may be readily adjusted to accommodate the volume of the mail and the speed with which manual operations required in the processing thereof may be accomplished. As pointed out above the facility according to the preferred embodiment may be readily divided into sectors adapted to operate independently of each other to allow the mail handling capability of the facility to be adjusted to match the volume of the mail at any particular point in time by using some or all ofsuch sectors.

Much of the equipment which would be utilized in the facility described hereinabove already exists in the prior art in various forms. it is of course possible to modify such equipment or to design new equipment in order to enable the realization of the full potential of the facility broadly described hereinabove. ln addition it is believed that the method and means of this invention may be applied in areas other than the handling of mail but related thereto in requirements. For example, the method and means of this invention might be used in the distribution of spare parts for electrical or mechanical equipment by the factory to a plurality of warehouses or outlets assuming that appropriate categories of physical characteristics for such parts could be established. Thus it is believed that those skilled in the art will find various applications for the method and means of this invention and that equipment of various types will be developed for the practice of such method and use in a facility in accordance with this invention. it will be understood that the structure housing a facility in accordance with this invention need not be circular although a circular structure is obviously inherently suited for a facility in accordance with this invention. Similarly the various receiving and distribution conveyors need not be of the carousel type in spite of the in herent advantages thereof. instead the method and means of this invention might be practiced by an in-line system. Thus it is believed that many embodiments of the method and means of this invention may be made by those skilled in the art.

What is claimed is:

l. The method of processing items of differing physical characteristics and each being designated for delivery to one of a plurality of destinations comprising the steps of:

a. separating said items into a plurality of categories by physical characteristics on a first level;

b. conveying the items of each of said categories by gravity to a different one ofa plurality of physically distinct areas on a vertically lower level;

ill

c. separating items of each of said categories by destination by transporting items of each of said categories horizontally for differing distances on said vertically lower level in accordance with the destination thereof;

d. conveying by gravity all items of each of said categories sorted to a particular destination to a common one of a plurality of physically distinct areas associated with said particular destination on a further still lower vertical level.

2. The method of processing mail received at a postal facility comprising the steps of:

a. separating that portion of said mail requiring special processing from the main body of said mail and, upon completion of said required special processing, returning all of said portion to said main body of said mail except mail requiring special handling other than by this method;

b. sorting said main body of said mail by physical characteristics and regardless of postal class into the following categories:

i. mixed mail ii. small parcels, rolls and flats iii. parcels iv. trayed mail v. bundled mail and directing each of said categories of said main body of said mail to a different one of a plurality of physically distinct areas for further processing;

c. culling said mixed mail to separate therefrom the small parcels, rolls, and flats and direct them to the appropriate one of said plurality of physically distinct areas for further processing with all other small parcels, rolls and flats;

d. directing the balance of said mixed mail to the appropriate one of said plurality of physically distinct areas for further processing with said trayed mail;

. further processing each of said categories comprising said small parcels, rolls and flats, said parcels, said trayed mail and said bundled mail in the appropriate physically distinct area therefor including the steps of separating the incoming portion of each from the outgoing portion thereof, sorting and storing for delivery said outgoing portion of each to appropriate intermediate destinations, and sorting and storing for delivery said incoming portion of each to appropriate groups of ultimate destinations.

3. A facility for processing mail received thereby, said facility having a plurality of superimposed levels:

a. the highest level of said facility comprising a first circular conveyor having inner and outer peripheries divided into a plurality of sets of compartments, each set of compartments including a compartment for each of a plurality of categories of mail by physical characteristics, said first circular conveyor being adapted to be loaded at a plurality of points about the outer periphery thereof and to be unloaded at a plurality of points about the inner periphery thereof;

b. a first gravity conveyor chute communicating between a first one of said plurality of points about the inner periphery of said first circular conveyor and a first lower level of said facility;

. a second gravity conveyor chute communicating between a second one of said plurality of points about the inner periphery of said first circular conveyor and a second lower level of said facility;

d. said second lower level of said facility including a pair of circular conveyors each having inner and outer peripheries, the inner periphery of one having a larger diameter than the outer periphery of the other, each of said pair of circular conveyors being adapted to be loaded and unloaded at a plurality of points about their inner and outer peripheries;

e. a third lower level of said facility including a plurality of storage bins; and

. a plurality of gravity conveyor chutes each communicating between a different one of said storage bins and a different point about the inner or outer periphery of one of said pair of circular conveyors.

4. A facility as claimed in claim 3, including a fourth lower level comprising a further circular having inner and outer peripheries and adapted to be loaded and unloaded at a plurality of points about said inner and outer periphery thereof and a plurality of gravity conveyor chutes each communicating between a different one of said plurality of storage bins an a different point about the inner or outer periphery of said further circular conveyor.

5. A facility as claimed in claim 3, wherein said first gravity conveyor chute is an inclined rectilinear chute and said second gravity conveyor chute is an inclined spiral chute.

6. A facility as claimed in claim 3, wherein an additional pair of circular conveyors each having inner and outer peripheries are included in said second lower level, the inner periphery of one of said circular conveyor having a larger diameter than the outer periphery of the other; each of said additional pair of circular conveyors being adapted to be loaded at a plurality of points and a plurality of gravity conveyor chutes each communicating between said first lower level and a different one of said plurality of points.

7. The method of processing within a facility items of differing physical characteristics each being designated for delivery to a different one of a plurality of ultimate destinations comprising the steps of:

a. separating said items into a plurality of categories by physical characteristics;

b. conveying each category of items to a different physically distinct area;

c. sorting said items of each category of items to a plurality of internal destinations at each of said physically distinct areas;

d. conveying items of all categories of physical characteristics sorted to a particular internal destination to said internal destination;

e. sorting said items at each of said intermediate destination to groups of ultimate destinations; and

f. conveying items sorted to each group of ultimate destinations to a different storage area corresponding to said group of ultimate destinations. 

1. The method of processing items of Differing physical characteristics and each being designated for delivery to one of a plurality of destinations comprising the steps of: a. separating said items into a plurality of categories by physical characteristics on a first level; b. conveying the items of each of said categories by gravity to a different one of a plurality of physically distinct areas on a vertically lower level; c. separating items of each of said categories by destination by transporting items of each of said categories horizontally for differing distances on said vertically lower level in accordance with the destination thereof; d. conveying by gravity all items of each of said categories sorted to a particular destination to a common one of a plurality of physically distinct areas associated with said particular destination on a further still lower vertical level.
 2. The method of processing mail received at a postal facility comprising the steps of: a. separating that portion of said mail requiring special processing from the main body of said mail and, upon completion of said required special processing, returning all of said portion to said main body of said mail except mail requiring special handling other than by this method; b. sorting said main body of said mail by physical characteristics and regardless of postal class into the following categories: i. mixed mail ii. small parcels, rolls and flats iii. parcels iv. trayed mail v. bundled mail and directing each of said categories of said main body of said mail to a different one of a plurality of physically distinct areas for further processing; c. culling said mixed mail to separate therefrom the small parcels, rolls, and flats and direct them to the appropriate one of said plurality of physically distinct areas for further processing with all other small parcels, rolls and flats; d. directing the balance of said mixed mail to the appropriate one of said plurality of physically distinct areas for further processing with said trayed mail; e. further processing each of said categories comprising said small parcels, rolls and flats, said parcels, said trayed mail and said bundled mail in the appropriate physically distinct area therefor including the steps of separating the incoming portion of each from the outgoing portion thereof, sorting and storing for delivery said outgoing portion of each to appropriate intermediate destinations, and sorting and storing for delivery said incoming portion of each to appropriate groups of ultimate destinations.
 3. A facility for processing mail received thereby, said facility having a plurality of superimposed levels: a. the highest level of said facility comprising a first circular conveyor having inner and outer peripheries divided into a plurality of sets of compartments, each set of compartments including a compartment for each of a plurality of categories of mail by physical characteristics, said first circular conveyor being adapted to be loaded at a plurality of points about the outer periphery thereof and to be unloaded at a plurality of points about the inner periphery thereof; b. a first gravity conveyor chute communicating between a first one of said plurality of points about the inner periphery of said first circular conveyor and a first lower level of said facility; c. a second gravity conveyor chute communicating between a second one of said plurality of points about the inner periphery of said first circular conveyor and a second lower level of said facility; d. said second lower level of said facility including a pair of circular conveyors each having inner and outer peripheries, the inner periphery of one having a larger diameter than the outer periphery of the other, each of said pair of circular conveyors being adapted to be loaded and unloaded at a plurality of points about their inner and outer peripheries; e. a third lower level of said facility including a plurality of storage bins; and f. a plurality of gravity conveyor chutes each communicating between a different one of said storage bins and a different point about the inner or outer periphery of one of said pair of circular conveyors.
 4. A facility as claimed in claim 3, including a fourth lower level comprising a further circular having inner and outer peripheries and adapted to be loaded and unloaded at a plurality of points about said inner and outer periphery thereof and a plurality of gravity conveyor chutes each communicating between a different one of said plurality of storage bins an a different point about the inner or outer periphery of said further circular conveyor.
 5. A facility as claimed in claim 3, wherein said first gravity conveyor chute is an inclined rectilinear chute and said second gravity conveyor chute is an inclined spiral chute.
 6. A facility as claimed in claim 3, wherein an additional pair of circular conveyors each having inner and outer peripheries are included in said second lower level, the inner periphery of one of said circular conveyor having a larger diameter than the outer periphery of the other; each of said additional pair of circular conveyors being adapted to be loaded at a plurality of points and a plurality of gravity conveyor chutes each communicating between said first lower level and a different one of said plurality of points.
 7. The method of processing within a facility items of differing physical characteristics each being designated for delivery to a different one of a plurality of ultimate destinations comprising the steps of: a. separating said items into a plurality of categories by physical characteristics; b. conveying each category of items to a different physically distinct area; c. sorting said items of each category of items to a plurality of internal destinations at each of said physically distinct areas; d. conveying items of all categories of physical characteristics sorted to a particular internal destination to said internal destination; e. sorting said items at each of said intermediate destination to groups of ultimate destinations; and f. conveying items sorted to each group of ultimate destinations to a different storage area corresponding to said group of ultimate destinations. 